Gastric Barotrauma in a Scuba Diver: Report of a Case

Stomach rupture can occur as a consequence of the expansion of compressed air during rapid ascent after diving. We present the case of a middle-aged woman who suffered a gastric tear from surfacing too quickly after diving, and discuss the diagnosis and management of such patients by reviewing previously reported similar events. Gastric barotrauma should be suspected in divers who complain of abdominal pain, even in the absence of frank signs of peritoneal irritation. Although pneumoperitoneum is always present in these patients, it can also occur as a consequence of pulmonary barotrauma, making gastroscopy or radiological contrast studies, or both, essential for a definitive diagnosis. Surgical repair represents the treatment of choice for an active full-thickness tear and, if associated with arterial gas embolism or decompression sickness, should ideally be performed in a center where a category I (intensive care-capable) hyperbaric unit is available. Received: March 18, 2002 / Accepted: September 3, 2002 Reprint requests to: L.V. Titu     

Efficacy, results, and complications of mechanical ventilation in children with status asthmaticus.

We have conducted a retrospective survey of 79 children out of a total hospital asthmatic patient population of 2,412, admitted over a 32 month period to the ICU for the management of severe status asthmaticus. All patients were in severe respiratory distress with CO2 retention; 19 required mechanical ventilation due to increasing fatigue and worsening bronchospasm, having failed to respond to either inhaled or IV bronchodilator therapy. All patients were ventilated at slow rates (less than 12 min) and their airway pressure (Paw) was deliberately kept below 45 cmH2O, while accepting a PaCO2 in the 45-60 mmHg range, as long as the pH was compensated. Although two patients developed pneumothoraces while on positive pressure ventilation, these were resolved without incidents. Five patients who had mediastinal or subcutaneous air leaks prior to intubation did not develop pneumothoraces. Following the initiation of mechanical ventilation, IV beta-agonist therapy was increased in order to reverse the bronchospasm and reduce the duration of mechanical ventilation. Mean duration of intubation was 42 hours. Fourteen of the 19 patients were weaned and extubated within 48 hours. All patients survived without sequelae. We conclude that a degree of controlled "hypoventilation" by deliberately choosing Paw less than 45 cmH2O can be successfully used to ventilate children with severe status asthmaticus with a reduced rate of pressure-related complications.     

Prophylaxis against middle ear barotrauma in US hyperbaric oxygen therapy centers

The most common complication of hyperbaric oxygen (HBO) treatment is middle ear barotrauma, which can lead to permanent hearing loss and vertigo. Unconscious patients and infants present a special diagnostic challenge because of difficulties in communicating pain and equalizing pressure across the ears. This study involved a phone survey to all hospital-based HBO centers in the United States concerning routine practice for middle ear barotrauma prophylaxis. Results indicate that more than a fifth of centers always do routine prophylactic myringotomies on intubated patients (30 of 126) and infants (19 of 86). Less than half of centers never performed the procedure as routine prophylaxis. A third of centers (49 of 145) routinely administered prophylactic drugs before HBO treatment. Topical nasal decongestants, particularly oxymetazoline, were preferred to systemic oral medications (χ² = 20.8, P < .001). These results show that there is great variance in clinical practice with regard to middle ear barotrauma prophylaxis among US HBO centers. Many centers are using unproven therapies such as topical nasal decongestants.     

不同气压变化速率对豚鼠耳气压伤的影响

为了解不同气压变化速率对中、内耳的影响，利用低压舱对40只豚鼠施以10种不同升、降速率（上升率／下降车为：20／20、20／100、50／20、50／100、100／20、100／100、150／20、150／100、200／20、200／100，m／s）的损伤实验。实验结果表明：前庭躯体反应的出现是因中耳腔的正压，而不是负压影响。咽鼓管机能不良和上升速率过快是本病的主要原因。下降速率增快可使鼓膜破裂数量增加，鼓膜的穿孔对避免内耳进一步损伤有积极作用，并且可因此减少发病率。圆窗膜和卵圆窗的损伤在本病中是较少发生的。变压性眩晕是一种伴随前庭终器明确病理改变的气压伤，并非一过性前庭功能失衡。     

An unusual type of severe barotrauma owing to automobile tire biting in a child

The authors report a rare case of a barotraumatic pneumothorax and pneumomediastinum associated with esophageal perforation and orbital emphysema. A 4-year-old boy presented with sudden respiratory distress after blowout of a defective tire that he bit. Computed tomography scan showed right pneumothorax and bilateral orbital emphysema. A linear rupture has been detected in the cervical esophagus in esophagoscopy. Stamm gastrostomy and tube thoracostomy were performed, and broad-spectrum antibiotics have been introduced. Oral feeding started 23 days after blowout of tire, and the patient was discharged 50 days after injury.     

高、低压舱致豚鼠耳气压损伤的形态学变化

目的 验证高压氧舱法和低压舱法检测咽鼓管通气功能时，引起实验豚鼠的中耳、内耳病理改变的一致性。方法 健康的杂色豚鼠38只随机分为3个高压氧舱组和3个低压舱组，分别在相应条件下进行模拟上升和下降实验，出舱电耳镜观察豚鼠鼓膜后处死，进行中耳及内耳组织学观察。结果 鼓膜反应及中耳、内耳组织学改变组间无差异。结论 本实验从病理形态学角度证实高压氧舱可以检测咽鼓管通气功能。     

Spontaneous aseptic pneumoperitoneum

Pneumoperitoneum indicates the need for urgent laparotomy. But under certain clinical situations like, patient on ventilatory support should arouse the suspicion of supradiaphragmatic source of pneumoperitoneum. Supradiaphragmatic causes account for 10%. This article describes two patients, both on ventilatory support in the intensive care unit. Failure to recognize spontaneous aseptic-pneumoperitoneum can result in unnecessary laparotomy with its risks. Hence under relevant circumstances, non-surgical causes of pneumopreitoneum should be excluded.     

Histologic aspects of pulmonary barotrauma in critically ill patients with acute respiratory failure

Objective To describe histologically pulmonary barotrauma in mechanically ventilated patients with severe acute respiratory failure.Design Assessment of histologic pulmonary barotrauma.Setting A 14-bed surgical intensive care unit (SICU).Patients The lungs of 30 young critically ill patients (mean age 34±10 years) were histologically examined in the immediate post-mortem period. None of them were suspected of pre-existing emphysema.Measurements and results Clinical events and ventilatory settings used during mechanical ventilation were compared with lung histology. Airspace enlargement, defined as the presence of either alveolar overdistension in aerated lung areas or intraparenchymal pseudocysts in nonaerated lung areas, was found in 26 of the 30 lungs examined (86%). Patients with severe airspace enlargement (2.6–40 mm internal diameter) had a significantly greater incidence of pneumothorax (8 versus 2,p<0.05), were ventilated using higher peak airway pressures (56±18 cmH₂O versus 44±10 cmH₂O,p<0.05) and tidal volumes (12±3 ml/kg, versus 9±2ml/kg,p<0.05) were exposed significantly longer to toxic levels of oxygen (8.6±9.4 days versus 1.9±2 days at FIO₂>0.6,p<0.05) and lost more weight (6.3±9.2 kg versus 0.75±5.8 kg,p<0.05) than patients with mild airspace enlargement (1–2.5 mm internal diameter).Conclusion Underlying histologic lesions responsible for clinical lung barotrauma consist of pleural cysts, bronchiolar dilatation, alveolar overdistension and intraparenchymal pseudocysts. Mechanical ventilation appears to be an aggravating factor, particularly when high peak airway pressures and large tidal volumes are delivered by the ventilator.Presented in part at the 32ème Congrès de la Société Française d'Anesthésie-Réanimation, Septembre 1990, Paris, France     

Pulmonary barotrauma including orbital emphysema following inhalation of toxic gas

Severe pulmonary barotrauma occurred following smoke and toxic gas inhalation in a 20-year-old male. He developed pneumothorax, pneumomediastinum, and extensive facial subcutaneous emphysema which intensified during treatment with positive pressure ventilation. Following the appearance of diplopia and exotropia, orbital emphysema was demonstrated radiologically. The diplopia and exotropia were manifestations of mechanical interference in extra-ocular muscle function by the intra-orbital air, an unusual expression of pulmonary barotrauma.